Field of the Invention
Embodiments of the invention generally relate to a method of forming an anti-reflective coating (ARC), and more particularly, for forming an ARC with a graded refractive index.
Description of the Background Art
Many of the materials used in manufacturing solar cells, for example silicon, have high refractive indices and result in loss of incident sunlight by reflection. Thin film materials having a series of layers of metals and dielectrics of varying dielectric constants and refractive indices, such as a graded anti-reflective coating (ARC), are used to reduce glare or reflection.
Graded ARCs are often deposited by chemical vapor deposition (CVD) or plasma enhanced CVD (PECVD). However, CVD and PECVD pose a challenge because they require deposition at higher temperatures and incorporate large amounts of hydrogen, therefore resulting in impurities and low film quality.
Therefore, there is a need for an improved method of forming an ARC with a graded refractive index.